Previous swimming pools having wave-generating apparatus have produced periodic waves or other forms of water motion at short regular intervals which are produced by periodic applications of energy, either through air pressure, water pressure, or other mechanical application. The energy is applied in a periodic fashion to produce the desired periodic waves. In systems incorporating air excitation, the water is displaced by periodic application of air pressure or partial vacuum to an auxiliary water displacement chamber or caisson located adjacent to the swimming pool which receives the periodically displaced water, producing the desired wave motion. The periodic wave-generating systems are limited to waves of relatively short periodicity. However, certain water sport activities such as surfing require a large wave with a longer period between each wave. The above-mentioned short-period wave generators cannot produce suitable waves for this purpose.
To produce the desired aperiodic or long-interval surf waves, one approach has been to construct a water reservoir adjacent to and above the water surface of the swimming pool; the release of the contained water into the swimming pool produces the desired wave by adding the volume and potential energy of the stored water. This form of wave generator is limited by the volume of water stored and the rate at which the water can be replaced within the above-mentioned reservoir. Also, the valves used to release water from the reservoir into the swimming pool are normally at least partially underwater at all times, reducing the life of such valves. The reservoir itself is expensive to build and to maintain. Moreover, the high profile of the reservoir is visually unattractive to the otherwise normal pool or natural beach surroundings.